Diastolic Blood Pressure and Left Ventricular Filling

Many factors appear to influence diastolic left ventricular (LV) filling, including age, hypertension, and myocardial and coronary disease. Doppler-echocardiography was used to asses the influences of blood pressure (BP) on LV filling in 43 normotensive volunteers aged 12 +/- 0.98 years with heart rates less than or equal to 90 beats/min. Doppler peak diastolic transmitral flow velocities, diastolic flow integrals, and early diastolic deceleration were measured. An interesting difference was noted between the influence of systolic and diastolic BP. Systolic BP was related to LV mass (r = 0.43; P less than 0.005), but was unrelated to any of the Doppler filling indices. Diastolic BP was unrelated to LV mass, but was inversely related to peak early diastolic flow velocity (r = -0.37; P less than 0.05), early diastolic flow velocity integral (r = -0.34; P less than 0.05). The ratio of late-to-early filling (A/E) was directly related to diastolic BP (r = 0.42; P less than 0.005). The relationship between A/E and diastolic BP was strong in subjects (n = 21) with bimodal P waves in electrocardiogram (ECG) lead V1 (r = 0.61; P less than 0.005), but absent in those (n = 15) with unimodal P waves (r = 0.18; P = NS). Thus, the pattern of LV filling is related to the level of diastolic BP in normal adolescents, especially in those with bimodal P waves on ECG. These diastolic BP related changes are independent of heart rate and LV hypertrophy and may represent very early pre-hypertensive alterations in LV diastolic function.